Heating and cooling electrical components in a downhole operation

CROSS-REFERENCE TO RELATED APPLICATION

0001This application is a divisional application of U.S. patent application Ser. No. 11/293,041, filed Dec. 2, 2005 and now abandoned; which application claims priority under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/633,181, filed Dec. 3, 2004, which applications are incorporated herein by reference in their entirety.

RELATED APPLICATIONS

0002This application may be related to U.S. Pat. No. 7,699,102, entitled: RECHARGEABLE ENERGY STORAGE DEVICE IN A DOWNHOLE OPERATION, Ser. No. 11/292,943, filed Dec. 2, 2005; and U.S. Pat. No. 7,717,167, entitled: SWITCHABLE POWER ALLOCATION IN A DOWNHOLE OPERATION, Ser. No. 11/293,868, filed Dec. 2, 2005.

TECHNICAL FIELD

0003The application relates generally to petroleum recovery operations. In particular, the application relates to a configuration for use of electronics in downhole tools for such operations.

BACKGROUND

0004During drilling operations, Measurement-While-Drilling (MWD) and Logging-While-Drilling (LWD systems as well as wireline systems provide wellbore directional surveys, petrophysical well logs and drilling information to locate and extract hydrocarbons from below the surface of the Earth. Different tools used in these operations incorporate various electrical components. Examples of such tools include sensors for measuring different downhole parameters, data storage devices, flow control devices, transmitters/receivers for data communications, etc. Downhole temperatures can vary between low to high temperatures, which can adversely affect the operations of the electrical components.

SUMMARY

0005In some embodiments, an apparatus includes a tool for a downhole operation. The tool includes a downhole power source to generate power. The tool also includes a cooler module to lower temperature based on the power.

BRIEF DESCRIPTION OF THE DRAWINGS

0006Embodiments of the invention may be best understood by referring to the following description and accompanying drawings which illustrate such embodiments. The numbering scheme for the Figures included herein are such that the leading number for a given reference number in a Figure is associated with the number of the Figure. For example, a tool <b>100</b> can be located in <figref idref="DRAWINGS">FIG. 1</figref>. However, reference numbers are the same for those elements that are the same across different Figures. In the drawings:

0007<figref idref="DRAWINGS">FIG. 1</figref> illustrates a tool for downhole operations that includes a configuration for electrical components operable at high temperatures, according to some embodiments of the invention.

0008<figref idref="DRAWINGS">FIG. 2</figref> illustrates a more detailed diagram of a tool for downhole operations that includes a configuration for electrical components operable at high temperatures, according to some embodiments of the invention.

0009<figref idref="DRAWINGS">FIGS. 3A-3B</figref> illustrate mechanical spring configurations as energy storage devices, according to some embodiments of the invention.

0010<figref idref="DRAWINGS">FIGS. 4A-4B</figref> illustrate hydrostatic chamber configurations as energy storage devices, according to some embodiments of the invention.

0011<figref idref="DRAWINGS">FIGS. 5A-5B</figref> illustrate elevated mass configurations as energy storage devices, according to some embodiments of the invention.

0012<figref idref="DRAWINGS">FIGS. 6A-6B</figref> illustrate differential pressure drive configurations as energy storage devices, according to some embodiments of the invention.

0013<figref idref="DRAWINGS">FIGS. 7A-7B</figref> illustrate compressed gas drive configurations as energy storage devices, according to some embodiments of the invention.

0014<figref idref="DRAWINGS">FIG. 8</figref> illustrates a more detailed diagram of a tool for downhole operations that includes a configuration for controlling power flow between heating and cooling, according to some embodiments of the invention.

0015<figref idref="DRAWINGS">FIG. 9</figref> illustrates a plot of the temperatures of two phase change materials as a function of time, according to some embodiments of the invention.

0016<figref idref="DRAWINGS">FIG. 10</figref> illustrates power and heat flow in a tool for downhole operations that includes a configuration for controlling power flow between heating and cooling, according to some embodiments of the invention.

0017<figref idref="DRAWINGS">FIG. 11</figref> illustrates a flow diagram for controlling power flow between heating and cooling, according to some embodiments of the invention.

0018<figref idref="DRAWINGS">FIG. 12</figref> illustrates power flow in a tool for downhole operations that includes a rechargeable energy storage device, according to some embodiments of the invention.

0019<figref idref="DRAWINGS">FIG. 13</figref> illustrates heat flow in a tool for downhole operations that includes a rechargeable energy storage device, according to some embodiments of the invention. Heat flows from a turbine generator <b>806</b> and a cooler <b>804</b> to a mud flow <b>808</b>.

0020<figref idref="DRAWINGS">FIG. 14A</figref> illustrates a more detailed diagram of a tool for downhole operations that includes rechargeable energy storage devices to supply power downhole, according to some embodiments of the invention.

0021<figref idref="DRAWINGS">FIG. 14B</figref> illustrates a more detailed diagram of a tool for downhole operations that includes rechargeable energy storage devices to supply power downhole, according to other embodiments of the invention.

0022<figref idref="DRAWINGS">FIG. 15A</figref> illustrates a drilling well during wireline logging operations that includes the heating and/or cooling downhole, according to some embodiments of the invention.

0023<figref idref="DRAWINGS">FIG. 15B</figref> illustrates a drilling well during MWD operations that includes the heating and/or cooling downhole, according to some embodiments of the invention.

DETAILED DESCRIPTION

0024Methods, apparatus and systems for heating and cooling downhole are described. In the following description, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known circuits, structures and techniques have not been shown in detail in order not to obscure the understanding of this description.

0025Some embodiments include configurations that have electrical components that are operable at high temperatures in combination with heat exhausting cooling systems. Some embodiments include different Commercial Off The Shelf (COTS) electronics (such as high density memory and microprocessors) that are enclosed in a thermally insulating container that may be cooled by a heat exhausting cooling system. The cooling system may include heat sinks, heat exchangers and other components for enhancing thermal energy transfer. Moreover, the configuration may include components capable of exhausting heat to the surrounding environment. For example, the tool pressure housing, drill string, etc. may be coupled to a heat sink, a heat exchanger, etc. to exhaust the heat. In some embodiments, certain electrical components may be operable at high temperatures. For example, the electrical components that are part of the power source (such as a flow-driven generator), the sensors, the telemetry components, etc. may be operable at high temperatures. Some embodiments allow the use of COTS microprocessors and memory downhole that are operable at low temperatures. Accordingly, the speed of processing may be greater and the density of the memory may be higher that can be obtained using high-temperature electrical components.

0026Some embodiments include a power generator that is switchably operated to provide power to both a heater and a cooler downhole. For example, if the temperature is low, some or all of the power may be switched to a heater that may be used to raise the temperature of an energy storage device. Conversely, if the temperature is high, some or all of the power may be switched to a cooler that may be used to lower the temperature of electronics.

0027Some embodiments include a rechargeable energy storage device, which may be used in combination with an alternative power source (such as a turbine generator powered by mud flow downhole). The rechargeable energy storage device may be operable a high temperatures. Rechargeable energy storage device operable at high temperatures exceed the operating temperature limit of standard energy storage devices (such as standard lithium batteries). Moreover, recharging the energy storage devices downhole may allow for a smaller storage device payload than would be required with non-rechargeable energy storage devices.

0028While described with reference to the removal of heat from electrical components, such embodiments may be used to remove heat from any type of component. For example, the component may be mechanical, electro-mechanical, etc. In the following description, the definition of high temperature and low temperature are defined for various components. Such definitions of temperature are relative to the component and may or may not be independent of temperatures of other components. For example, a high temperature for component A may be different than a high temperature for component B.

0029This description of the embodiments is divided into four sections. The first section describes a tool in a downhole operation. The second section describes different configurations for a switchably operated downhole power source for heating and cooling in a downhole tool. The third section describes different configurations using a rechargeable energy storage devices downhole. The fourth section describes example operating environments. The fifth section provides some general comments.

Downhole Tool Having Heating and/or Cooling

0030<figref idref="DRAWINGS">FIG. 1</figref> illustrates a tool for downhole operations that includes a configuration for electrical components operable at high temperatures, according to some embodiments of the invention. In particular, <figref idref="DRAWINGS">FIG. 1</figref> illustrates a tool <b>100</b> that may be representative of a downhole tool that is part of an MWD system, a tool body that is part of a wireline system, a temporary well testing tool, etc. Examples of such systems are described in more detail below (see description of <figref idref="DRAWINGS">FIGS. 10A-10B</figref>). The tool <b>100</b> includes a high-temperature power source <b>102</b>, a cooler module <b>104</b>, a thermal barrier <b>106</b> and a high-temperature sensor section <b>108</b>.

0031In some embodiments, the cooler module <b>104</b> includes one or more heat exchangers or other components for thermal energy transfer. The heat exchangers may be parallel-flow heat exchangers, wherein two fluids enter an exchanger at a same end and travel the exchanger parallel relative to each other. The heat exchangers may be counter-flow heat exchangers wherein the two fluids enter an exchanger at opposite ends. The heat exchangers may also be cross-flow heat exchangers, plate heat exchangers, etc. The heat exchangers may be comprised of multiple layers of different materials, such as copper flow tubes with aluminum fins or plates. In some embodiments, the cooler module includes a thermoacoustic cooler which is capable of removing heat from one area of the tool, such as that area occupied by thermally sensitive electronics, and transferring this heat to some other area which is not as temperature sensitive.

0032The thermal barrier <b>106</b> may be a thermally insulating container. The thermal barrier <b>106</b> may house different electronics or electrical components. For example, the thermal barrier <b>106</b> may house electronics or electrical components that are operable at low temperatures. In some embodiments, such electronics or electrical components are COTS electronics. The high-temperature sensor section <b>108</b> includes one to a number of different sensors that include electrical components that are operable at high temperatures. Alternatively, some of the electrical components that are capable of operating at high temperature may be housed in the thermal barrier <b>106</b> and operable at low temperatures.

0033<figref idref="DRAWINGS">FIG. 2</figref> illustrates a more detailed diagram of a tool for downhole operations that includes a configuration for electrical components operable at high temperatures, according to some embodiments of the invention. In particular, <figref idref="DRAWINGS">FIG. 2</figref> illustrates a more detailed block diagram of the tool <b>100</b>. The tool <b>100</b> includes a high-temperature power source <b>202</b>, high-temperature power conditioning electronics <b>204</b>, an energy storage device <b>203</b>, the cooler module <b>104</b>, low-temperature electronics <b>206</b>, the thermal barrier <b>106</b>, high-temperature telemetry <b>212</b> and sensors <b>214</b>A-<b>214</b>N. In some embodiments, not all of the components of the tool <b>100</b> illustrated in <figref idref="DRAWINGS">FIG. 2</figref> are incorporated therein. For example, the tool <b>100</b> may not include the energy storage device <b>203</b>. In another example, the tool <b>100</b> may not include the high-temperature telemetry <b>212</b>.

0034The high-temperature power source <b>202</b> is coupled to the high-temperature power conditioning electronics <b>204</b>. The high-temperature power source <b>202</b> may provide power to different electrical loads in the tool <b>100</b>. For example, the different electrical loads may include the low-temperature electronics <b>206</b>, the cooler module <b>104</b>, the sensors <b>214</b>A-<b>214</b>N, the high-temperature telemetry <b>212</b>, the energy storage device <b>203</b>, etc. The high-temperature power source <b>202</b> may be of different types. The high-temperature power source <b>202</b> may produce any power waveform including alternating current (AC) or direct current (DC). For example, the high-temperature power source <b>202</b> may be a flow-driven generator that derives its power from the mud flow in the borehole, a vibration-based generator, etc. The high-temperature power source <b>202</b> may be of the axial, radial or mixed flow type. In some embodiments, the high-temperature power source <b>108</b> may be driven by a positive displacement motor driven by the drilling fluid, such as a Moineau-type motor.

0035The high-temperature power conditioning electronics <b>204</b> may receive and condition the power from the high-temperature power source <b>202</b>. The high-temperature power source <b>202</b> may be positioned near the sensors <b>214</b>A-<b>214</b>N which may be near the drill bit of the drill string. The high-temperature power source <b>202</b> may be positioned further uphole near the repeaters that may be part of the telemetry system.

0036The high-temperature power source <b>202</b> and the high-temperature power conditioning electronics <b>204</b> may include electrical components that are operable at high temperatures. The electrical components may be composed of Silicon On Insulator (SOI), such as Silicon On Sapphire (SOS). In some embodiments, high temperatures in which the electrical components in the high-temperature power source <b>102</b> and the high-temperature power conditioning electronics <b>204</b> are operable include temperature above 150 degrees Celsius (° C.), above 175° C., above 200° C., above 220° C., in a range of 175-250° C., in a range of 175-250° C., etc.

0037The thermal barrier <b>106</b> hinders heat transfer from the outside environment to the electronics or electrical components housed in the thermal barrier <b>106</b>. In some embodiments, the thermal barrier <b>106</b> may include an insulated vacuum flask, a vacuum flask filled with an insulating solid, a material-filled chamber, a gas-filled chamber, a fluid-filled chamber, or any other suitable barrier. In some embodiments, there may be a space between the thermal barrier <b>106</b> and the outside wall of the tool <b>100</b>. This space may be evacuated, thereby hindering the heat transfer from outside the tool <b>100</b> to the electrical components within the thermal barrier <b>106</b>. In some embodiments, the thermal barrier <b>106</b> may house the low-temperature electronics <b>206</b>, at least part of the cooler module <b>104</b> and at least part of the sensors <b>214</b>A-<b>214</b>N. The low temperatures at which these electrical components may be operable include temperatures below 150° C., below 175° C., below 200° C., below 220° C., below 125° C., below 100° C., below 80° C., in a range of 0-80° C., in a range of −20-100° C., etc.

0038In some embodiments, the sensors <b>214</b>A-<b>214</b>N are composed of high-temperature electronics and are not housed in thermal barrier <b>106</b>. Accordingly, the sensors <b>214</b>A-<b>214</b>N may withstand direct contact with an environment at excessive temperatures. In some embodiments, at least part of the sensors <b>214</b>A-<b>214</b>N have components not capable of operation at excessive environmental temperatures. In such a configuration, the thermally sensitive components of these sensors <b>214</b>A-<b>214</b>N may be partially or totally enclosed in the thermal barrier <b>106</b>. Alternatively or in addition, these thermally sensitive components of these sensors <b>214</b>A-<b>214</b>N may be coupled to the cooler module <b>104</b>. Therefore, these thermally sensitive components may be maintained at or below their operating temperatures. The sensors <b>214</b>A-<b>214</b>N may be representative of any type of electronics or devices for sensing, control, data storage, telemetry, etc.

0039The sensors <b>214</b>A-<b>214</b>N may be different types of sensors for measurement of different parameters and conditions downhole, including the temperature and pressure, the various characteristics of the subsurface formations (such as resistivity, porosity, etc.), the characteristics of the borehole (e.g., size, shape, etc.), etc. The sensors <b>214</b>A-<b>214</b>N may also include directional sensors for determining direction of the borehole. The sensors <b>214</b>A-<b>214</b>N may include electromagnetic propagation sensors, nuclear sensors, acoustic sensors, pressure sensors, temperature sensors, etc.

0040The electrical components within the high-temperature part of the sensors <b>214</b> may be composed of Silicon On Insulator (SOI), Silicon On Sapphire (SOS), Silicon Carbide, etc. In some embodiments, high temperatures in which the electrical components of the high-temperature parts of the sensors <b>214</b> are operable include temperature above 150 degrees Celsius (° C.), above 175° C., above 200° C., above 220° C., in a range of 175-250° C., in a range of 175-250° C., etc. In some embodiments, the low temperature at which the electrical components of the low-temperature parts of the sensors are operable includes temperature below 150° C., below 175° C., below 200° C., below 220° C., below 125° C., below 100° C., below 80° C., in a range of 0-80° C., in a range of −20-100° C., etc. In some embodiments, high temperatures in which the electrical components of the high-temperature telemetry <b>212</b> are operable include temperature above 150 degrees Celsius (° C.), above 175° C., above 200° C., above 220° C., in a range of 175-250° C., in a range of 175-250° C., etc.

0041Power may be supplied to the cooler module <b>104</b> from the high-temperature power source <b>202</b>. Alternatively or in addition, power may be supplied to the cooler module <b>104</b> directly from the flow of the fluid in the borehole. If the cooler module <b>104</b> is driven by the fluid flow, a magnetic torque coupler may be used to avoid the use of dynamic seals by allowing mechanical coupling through a mechanical fluid barrier. This arrangement provides for direct mechanical powering of the cooler. Additionally, mechanical power provided by the fluid flow may be used to drive a hydraulic or pneumatic pump which can then be used to drive a hydraulic or pneumatic motor or other components to provide the mechanical drive for the cooler. In some embodiments, the cooler module <b>104</b> may include a thermoacoustic cooler. A thermoacoustic cooler typically operates at substantially the same speed, while the fluid flow rate may vary significantly. Therefore, a variable speed clutch may be used to provide a constant rotation rate to the cooler module <b>104</b>. The variable speed clutch may have a mechanical transmission or may use a variable rheological fluid, such as magnetorheological fluid. Additionally, the rotation rate may be varied by changing the angle of the fin on the blades of the generator in the fluid flow. At high flow rates, a brake may be used to limit the rotation speeds of the blades. The power from the high-temperature power source <b>202</b> may be electrical and/or mechanical. For example, the cooler module <b>104</b> may be powered directly with mechanical energy. In other words, the fluid flow may cause mechanical motion, which provides the power to the cooler module <b>104</b>. Alternatively or in addition, the fluid flow may cause mechanical motion that generates electrical energy that generates mechanical motion, which provides the power to the cooler module <b>104</b>.

0042The energy storage device <b>203</b> may be any energy storage device suitable for providing power to downhole tools. Examples of energy storage devices include a primary (i.e., non-rechargeable) battery such as a voltaic cell, a lithium battery, a molten salt battery, or a thermal reserve battery, a secondary (i.e., rechargeable) battery such as a molten salt battery, a solid-state battery, or a lithium-ion battery, a fuel cell such as a solid oxide fuel cell, a phosphoric acid fuel cell, an alkaline fuel cell, a proton exchange membrane fuel cell, or a molten carbonate fuel cell, a capacitor, a heat engine such as a combustion engine, and combinations thereof. The foregoing energy storage devices are well known in the art. Suitable batteries are disclosed in U.S. Pat. No. 6,672,382 (describes voltaic cells), U.S. Pat. Nos. 6,253,847, and 6,544,691 (describes thermal batteries and molten salt rechargeable batteries), each of which is incorporated by reference herein in its entirety. Suitable fuel cells for use downhole are disclosed in U.S. Pat. Nos. 5,202,194 and 6,575,248, each of which is incorporated by reference herein in its entirety. Additional disclosure regarding the use of capacitors in wellbores can be found in U.S. Pat. Nos. 6,098,020 and 6,426,917, each of which is incorporated by reference herein in its entirety. Additional disclosure regarding the use of combustion engines in wellbores can be found in U.S. Pat. No. 6,705,085, which is incorporated by reference herein in its entirety.

0043The energy storage device <b>203</b> may provide power to different electrical loads in the tool <b>100</b>. For example, the different electrical loads may include the low-temperature electronics <b>102</b>, the cooling system <b>104</b>, the sensors <b>114</b>A-<b>114</b>N, the high-temperature telemetry <b>112</b>, etc. The energy storage device <b>203</b> may have relatively high minimum operating temperatures, which are commonly determined and provided by suppliers and/or manufacturers of energy storage devices. By way of example, the minimum operating temperatures of some high-temperature energy storage devices are as follows: a sodium/sulfur molten salt battery (typically a secondary battery) operates at from about 290° C. to about 390° C.; a sodium/metal chloride (e.g., nickel chloride) molten salt battery (typically a secondary battery) operates at from about 220° C. to about 450° C.; a lithium aluminum/iron disulfide molten salt battery operates near about 500° C.; a calcium/calcium chromate battery operates near about 300° C.; a phosphoric acid fuel cell operates at from about 150° C. to about 250° C.; a molten carbonate fuel cell operates at from about 650° C. to about 800° C.; and a solid oxide fuel cell operates at from about 800° C. to about 1,000° C.

0044In some embodiments, the energy storage device <b>203</b> may be based on different types of mechanical spring configurations. <figref idref="DRAWINGS">FIGS. 3A-3B</figref> illustrate mechanical spring configurations as energy storage devices, according to some embodiments of the invention. <figref idref="DRAWINGS">FIG. 3A</figref> illustrates an energy storage device that includes a torsional power spring, according to some embodiments of the invention. In particular, <figref idref="DRAWINGS">FIG. 3A</figref> illustrates an energy storage device <b>300</b> that includes a torsional power spring <b>302</b> to store power. The torsional power spring <b>302</b> is coupled to a power source <b>308</b> through a drive shaft <b>304</b>. Accordingly, the torsional power spring <b>302</b> may supply power to the power source <b>308</b> for powering components in the tool <b>100</b>.

0045<figref idref="DRAWINGS">FIG. 3B</figref> illustrates an energy storage device that includes a compression spring, according to some embodiments of the invention. In particular, <figref idref="DRAWINGS">FIG. 3B</figref> illustrates an energy storage device <b>320</b> that includes a spring <b>322</b> within an exhaust chamber <b>324</b>. The spring <b>322</b> is to store power. The spring <b>322</b> is coupled to a power source <b>328</b> through a hydraulic fluid <b>326</b>. Accordingly, the spring <b>322</b> may supply power to the power source <b>328</b> for powering components in the tool <b>100</b>.

0046In some embodiments, the energy storage device <b>203</b> may be based on different types of hydrostatic chamber configurations. <figref idref="DRAWINGS">FIGS. 4A-4B</figref> illustrate hydrostatic chamber configurations as energy storage devices, according to some embodiments of the invention. <figref idref="DRAWINGS">FIG. 4A</figref> illustrates an energy storage device that includes a hydrostatically-driven mechanical system, according to some embodiments of the invention. In particular, <figref idref="DRAWINGS">FIG. 4A</figref> illustrates an energy storage device <b>400</b> that includes hydrostatic pressure <b>402</b>. The hydrostatic pressure <b>402</b> is positioned adjacent to a drive piston <b>404</b> (that may be non-rotating). The energy storage device <b>400</b> also includes a torsion shaft <b>406</b> positioned adjacent to the drive piston <b>404</b> (opposite the hydrostatic pressure <b>402</b>). The energy storage device <b>400</b> includes a speed increaser <b>406</b> positioned adjacent to the torsion shaft <b>406</b> (opposite the drive piston <b>404</b>). The energy storage device <b>400</b> includes a drive shaft <b>410</b> positioned adjacent to the speed increaser <b>408</b> (opposite the torsion shaft <b>406</b>). The energy storage device <b>400</b> includes a power source <b>412</b> positioned adjacent to the drive shaft <b>410</b> (opposite the speed increaser <b>408</b>).

0047The energy storage device <b>400</b> also includes an exhaust chamber <b>414</b> positioned adjacent to the power source <b>412</b> (opposite the drive shaft <b>410</b>).

0048<figref idref="DRAWINGS">FIG. 4B</figref> illustrates an energy storage device that includes a hydrostatically-driven hydraulic system, according to some embodiments of the invention. In particular, <figref idref="DRAWINGS">FIG. 4B</figref> illustrates an energy storage device <b>420</b> that includes hydrostatic pressure <b>422</b>. The hydrostatic pressure <b>422</b> is positioned adjacent to a piston <b>424</b> (that may be floating). The energy storage device <b>420</b> also includes a hydraulic fluid <b>426</b> that is positioned adjacent to the piston <b>424</b> (opposite the hydrostatic pressure <b>422</b>). The energy storage device <b>420</b> includes a power source <b>428</b> that is positioned adjacent to the hydraulic fluid <b>426</b> (opposite the piston <b>424</b>). The energy storage device <b>420</b> includes an exhaust chamber <b>430</b> that is positioned adjacent to the power source <b>428</b> (opposite the hydraulic fluid <b>426</b>).

0049In some embodiments, the energy storage device <b>203</b> may be based on different types of elevated mass configurations. <figref idref="DRAWINGS">FIGS. 5A-5B</figref> illustrate elevated mass configurations as energy storage devices, according to some embodiments of the invention. <figref idref="DRAWINGS">FIG. 5A</figref> illustrates an energy storage device that includes a mass-driven mechanical system. In particular, <figref idref="DRAWINGS">FIG. 5A</figref> illustrates an energy storage device <b>500</b> that includes a mass <b>502</b>. The mass <b>502</b> is positioned adjacent to a torsion shaft <b>504</b>. The energy storage device <b>500</b> also includes a speed increaser <b>506</b> positioned adjacent to the torsion shaft <b>504</b> (opposite the mass <b>502</b>). The energy storage device <b>500</b> also includes a drive shaft <b>508</b> positioned adjacent to the speed increaser <b>506</b> (opposite the torsion shaft <b>504</b>). The energy storage device also includes a power source <b>510</b> positioned adjacent to the drive shaft <b>508</b> (opposite the speed increaser <b>506</b>).

0050<figref idref="DRAWINGS">FIG. 5B</figref> illustrates an energy storage device that includes a mass-driven hydraulic system. In particular, <figref idref="DRAWINGS">FIG. 5B</figref> illustrates an energy storage device <b>520</b> that includes a mass <b>522</b> within an exhaust chamber <b>524</b>. The exhaust chamber <b>524</b> is positioned adjacent to hydraulic fluid <b>526</b>. The energy storage device <b>500</b> also includes a power source <b>528</b> positioned adjacent to the hydraulic fluid <b>526</b> (opposite the exhaust chamber <b>524</b>).

0051In some embodiments, the energy storage device <b>203</b> may be based on different types of differential pressure drive configurations. <figref idref="DRAWINGS">FIGS. 6A-6B</figref> illustrate differential pressure drive configurations as energy storage devices, according to some embodiments of the invention. <figref idref="DRAWINGS">FIG. 6A</figref> illustrates an energy storage device that includes a differential pressure-driven mechanical system. In particular, <figref idref="DRAWINGS">FIG. 6A</figref> illustrates an energy storage device <b>600</b> that includes an annulus pressure port <b>602</b>. The annulus pressure port <b>602</b> is positioned adjacent to a drive piston <b>604</b> (which may be non-rotating). The energy storage device <b>600</b> also includes a torsion shaft <b>606</b> positioned adjacent to the drive piston <b>604</b> (opposite the annulus pressure port <b>602</b>). The energy storage device <b>600</b> also includes a speed increaser <b>608</b> positioned adjacent to the torsion shaft <b>606</b> (opposite the drive piston <b>604</b>). The energy storage device <b>600</b> also includes a drive shaft <b>610</b> positioned adjacent to the speed increaser <b>608</b> (opposite the torsion shaft <b>606</b>). The energy storage device <b>600</b> also includes a power source <b>612</b> positioned adjacent to the drive shaft <b>610</b> (opposite the speed increaser <b>608</b>). The energy storage device <b>600</b> includes a tubing pressure port <b>614</b> positioned adjacent to the power source <b>612</b> (opposite the drive shaft <b>610</b>).

0052<figref idref="DRAWINGS">FIG. 6B</figref> illustrates an energy storage device that includes a differential pressure-driven hydraulic system. In particular, <figref idref="DRAWINGS">FIG. 6B</figref> illustrates an energy storage device <b>620</b> that includes an annulus pressure port <b>622</b>. The annulus pressure port <b>622</b> is positioned adjacent to a piston <b>624</b> (which may be floating). The energy storage device <b>620</b> also includes hydraulic fluid <b>626</b> positioned adjacent to the piston <b>624</b> (opposite the annulus pressure port <b>622</b>). The energy storage device <b>620</b> also includes a power source <b>628</b> positioned adjacent to the hydraulic fluid <b>626</b> (opposite the piston <b>624</b>). The energy storage device <b>620</b> also includes a tubing pressure port <b>630</b> positioned adjacent to the power source <b>628</b> (opposite the hydraulic fluid <b>626</b>).

0053In some embodiments, the energy storage device <b>203</b> may be based on different types of compressed gas drive configurations. <figref idref="DRAWINGS">FIGS. 7A-7B</figref> illustrate compressed gas drive configurations as energy storage devices, according to some embodiments of the invention. <figref idref="DRAWINGS">FIG. 7A</figref> illustrates an energy storage device that includes a compressed gas-driven mechanical system. In particular, <figref idref="DRAWINGS">FIG. 7A</figref> illustrates an energy storage device <b>700</b> that includes an inert gas charge <b>702</b>. The inert gas charge <b>702</b> is positioned adjacent to a drive piston <b>704</b> (which may be non-rotating). The energy storage device <b>700</b> also includes a torsion shaft <b>706</b> positioned adjacent to the drive piston <b>704</b> (opposite the inert gas charge <b>702</b>). The energy storage device <b>700</b> also includes a speed increaser <b>708</b> positioned adjacent to the torsion shaft <b>706</b> (opposite the drive piston <b>704</b>). The energy storage device <b>700</b> also includes a drive shaft <b>710</b> positioned adjacent to the speed increaser <b>708</b> (opposite the torsion shaft <b>706</b>). The energy storage device <b>700</b> also includes a power source <b>712</b> positioned adjacent to the drive shaft <b>710</b> (opposite the speed increaser <b>708</b>). The energy storage device <b>700</b> includes an exhaust chamber <b>714</b> positioned adjacent to the power source <b>712</b> (opposite the drive shaft <b>710</b>).

0054<figref idref="DRAWINGS">FIG. 7B</figref> illustrates an energy storage device that includes a compressed gas-driven hydraulic system. In particular, <figref idref="DRAWINGS">FIG. 7B</figref> illustrates an energy storage device <b>720</b> that includes an inert gas charge <b>722</b>. The inert gas charge <b>722</b> is positioned adjacent to a piston <b>724</b> (which may be floating). The energy storage device <b>720</b> also includes hydraulic fluid <b>726</b> positioned adjacent to the piston <b>724</b> (opposite the inert gas charge <b>722</b>). The energy storage device <b>720</b> also includes a power source <b>728</b> positioned adjacent to the hydraulic fluid <b>726</b> (opposite the piston <b>724</b>). The energy storage device <b>720</b> includes an exhaust chamber <b>730</b> positioned adjacent to the power source <b>728</b> (opposite the hydraulic fluid <b>726</b>).

0055Therefore, as described, some embodiments provide a combination of low-temperature electrical components (such as those housed in the thermal barrier <b>106</b>) with high-temperature electrical components (such as those that are part of the high-temperature power source <b>202</b>, high-temperature power conditioning electronics <b>204</b>, high-temperature telemetry <b>212</b>, sensors <b>214</b>, etc) for downhole operations.

Switchably Operated Downhole Power Source for Heating and Cooling

0056In some embodiments, a controller may be used to control the flow of power in the tool <b>100</b>. <figref idref="DRAWINGS">FIG. 8</figref> illustrates a more detailed diagram of a tool for downhole operations that includes a configuration for controlling power flow between heating and cooling, according to some embodiments of the invention. In particular, <figref idref="DRAWINGS">FIG. 8</figref> illustrates a more detailed block diagram of parts of the tool <b>100</b>. <figref idref="DRAWINGS">FIG. 8</figref> includes a power source <b>802</b> coupled to a controller <b>824</b>. The controller <b>824</b> is coupled to sensors <b>812</b>. The controller <b>824</b> is also coupled to heaters <b>806</b> and a cooler module <b>822</b>.

0057The heaters <b>806</b> are thermally coupled to an energy storage device <b>804</b>. The cooler module <b>822</b> is thermally coupled to the electronics <b>820</b>. The thermal coupling may be through conduction, convection, radiation, etc. An optional thermal barrier <b>816</b> may also at least partially surround the heaters <b>806</b>, the sensor <b>812</b> and the energy storage device <b>804</b>. An optional thermal barrier <b>818</b> may also at least partially surround the cooler module <b>822</b>, the electronics <b>820</b> and the sensor <b>812</b>. The heaters <b>806</b> may be ohmic resistive heaters. The power source <b>802</b> and the cooler module <b>822</b> may be similar to the power source and the cooler module, illustrated in <figref idref="DRAWINGS">FIG. 2</figref>, respectively.

0058Optional heat sinks <b>835</b> may be thermally coupled to the heaters <b>806</b>. The heat sinks <b>835</b> for the heaters <b>806</b> allows for heat energy to be given to the energy storage device <b>804</b> at times when energy is not be consumed by other components. For example, the heat may be given to the phase change material within the heat sinks <b>835</b> near the surface from a power source near the surface. The heat sinks <b>835</b> may supply heat to the energy storage device <b>804</b> during transit through the cold part of the borehole. Additionally, the heat sinks <b>835</b> coupled to the heaters <b>806</b> may increase the duration where the heaters <b>806</b> may remain off, thus providing additional time for using the electronics <b>820</b>.

0059An optional heat sink <b>836</b> may be thermally coupled to the electronics <b>820</b>. In some embodiments, the heat sink <b>835</b> and/or the heat sink <b>836</b> include a phase change material. In some embodiments, the heat sink <b>835</b> and/or the heat sink <b>836</b> include more than one phase change material. Such a heat sink may be used to trigger events based on the state of the phase change material. In some embodiments, the heat sinks <b>835</b>/<b>836</b> may be composed of two phase change materials. <figref idref="DRAWINGS">FIG. 9</figref> illustrates a plot of temperature of two phase change materials within a heat sink as a function of time, according to some embodiments of the invention. As illustrated, a graph <b>900</b> includes temperature as a function of time for phase change material A and phase change material B. The melting temperature of material A (<b>902</b>) is lower than the melting temperature of material B (<b>904</b>). The temperature rises until a melting temperature of material A is reached (<b>906</b>). After the material A is melted, the temperature rises (<b>908</b>). The temperature rises until the melting temperature of material B is reached (<b>910</b>). This second plateau provides a warning that the two phase change materials in the heat sink are about to be exhausted.

0060For example, the impending exhaustion of the phase change material may trigger one or more events. An example of an event may be the turning down or off of high-powered devices to reduce the amount of heat generated. In another example, a given change in the phase change material may trigger a signal to the operator to exit the hole. For example, a change in the phase change material may represent an overheating downhole. Another example of an event may be a feedback indicator to the heater/cooler system that more or less power needs to be applied to increase or decrease the heating/cooling capability. Another example of an event may be an activation of an auxiliary or backup heating/cooling supply (such as an exothermal/endothermal chemical reaction). In some embodiments, the state of the phase change material may serve as a predictor of the performance of the system, diagnostic evaluation, etc. The temperature of the phase change material may be monitored to optimize the performance of the heating and/or cooling system.

0061While described with two phase change materials, a lesser or greater number of material may be used. If more parts are used, a more precise estimate of the usage of the heat sink may be obtained. In some embodiments, the parts of the phase change material are not miscible. The miscibility may be controlled by making the materials hydrophobic/hydrophilic, by making emulsions of the phase change materials. In some embodiments, if the phase change materials are mixed together, the materials may be physically separated. For example, one of the materials may be encapsulated in metal, plastic, glass, ceramic, etc. The phase change materials could both be placed in the voice space of a foam.

0062With reference to <figref idref="DRAWINGS">FIG. 9</figref>, the two phase change materials may be applied with a wide ΔT between the melting of material A and material B. In such a situation, the electrical components thermally coupled to the heat sink (e.g., the energy storage device <b>804</b> (shown in <figref idref="DRAWINGS">FIG. 8</figref>)) may be configured to operate in the temperature range between the melting temperature of material A and the melting temperature of material B. Thus, there is a heat sink, material A, to keep the electrical component cool enough for operation. There is also a heat sink, material B, to prevent the electrical component from over heating when the ambient temperature is too high, the thermostat on the heater failed, the internal heating from high power usage generated too much heat, etc. The composition of the heat sinks <b>835</b>/<b>836</b> is not limited to phase change material. For example, the heat sinks <b>835</b>/<b>836</b> may also be composed of various metals, such as copper, aluminum, etc.

0063Returning to <figref idref="DRAWINGS">FIG. 8</figref>, energy stored in the energy storage device <b>804</b> may be used to supply power to an electrical load <b>810</b>, the heaters <b>806</b>, the cooler module <b>822</b>, the electronics <b>820</b>, etc. The electrical load <b>810</b> may represent different electrical loads downhole. Referring to <figref idref="DRAWINGS">FIG. 2</figref>, for example, the electrical load <b>810</b> may include the sensors <b>214</b>, the high-temperature telemetry <b>212</b>, etc. The power source <b>802</b> may also supply power to the electrical load <b>810</b>, the electronics <b>820</b>, etc.

0064Moreover, the power source <b>802</b> may be switchably operated to provide power to both the heaters <b>806</b> and the cooler module <b>822</b>. In some embodiments, at a low temperature, a greater percentage or all of the power from the power source <b>802</b> is supplied to the heaters <b>806</b>. Conversely, at a high temperature, a greater percentage or all of the power from the power source <b>802</b> is supplied to the cooler module <b>822</b>.

0065Power scheduling among the heating and cooling may allow for a smaller power generator. In particular, the total power for the simple sum of the loads may be larger than the power that can be provided by the power source <b>802</b>. This is possible because in some embodiments, not all of the loads are used simultaneously. In some embodiments, the power source <b>802</b> derives power from the mud flow downhole. Power scheduling may allow for full operation at lower flow rates.

0066The controller <b>824</b> may be a direct wire connection, an inductive couple, a feedback controller, a feedforward controller, a pre-programmed timing-based controller, a neural network controller, an adaptive controller, etc. that allows power to flow between the power source <b>802</b> and the heaters <b>806</b>, and the power source <b>802</b> and the cooler module <b>822</b>. For example, in some embodiments, the controller <b>824</b> may be a pulse-width modulation controller that changes the pulse widths to adjust the duty cycle of the applied voltage.

0067The controller <b>824</b> is shown to control the distribution of power based on input from the sensors <b>812</b>. The sensors <b>812</b> are shown to monitor the temperature of the energy storage device <b>804</b> and the electronics <b>820</b>. Embodiments are not so limited. For example, the controller <b>824</b> may control based on input from either (and not necessarily both) of the sensors <b>812</b>. Alternatively or in addition, the controller <b>824</b> may control based on another sensor (not shown) that is positioned to measure the ambient temperature downhole. Alternatively or in addition, the controller <b>824</b> may control based on the temperature of the phase change material within the heat sink <b>835</b> and/or the heat sink <b>836</b>. In some embodiments, the heaters <b>806</b> and the cooler module <b>822</b> may adjust the amount of power to accept from the controller <b>824</b>. For example, if the cooler module <b>822</b> does not need power for cooling, the cooler module <b>822</b> may include its own controller to adjust how much power to accept. Optional thermostats may be coupled to the heaters <b>806</b> and the cooler module <b>822</b>. Control may be based on a temperature reference from the thermostats for the energy storage device <b>804</b>/electronics <b>820</b> or for the heat sinks <b>835</b>/<b>836</b>.

0068In some embodiments, the energy storage device <b>804</b> may be the thermal barrier <b>818</b>. Accordingly, the energy storage device <b>804</b> may be such devices that are operable at low temperatures (such as a primary lithium battery). In some embodiments, the tool may include multiple energy storage devices where one or more may be positioned outside the thermal barrier <b>818</b> and one or more may be housed in the thermal barrier <b>818</b>. In some embodiments, the heat sink <b>836</b> may be positioned between the cooler module <b>822</b> and the electronics <b>820</b>. In one such configuration, the heat sinks <b>835</b> may be absent.

0069<figref idref="DRAWINGS">FIG. 10</figref> illustrates power and heat flow in a tool for downhole operations that includes a configuration for controlling power flow between heating and cooling, according to some embodiments of the invention. The power flow and the heat flow are illustrated by the solid lines and dashed lines, respectively. The power source <b>802</b> is represented as a turbine <b>1006</b> that receives power from a flow <b>1004</b> of mud downhole.

0070The controller <b>824</b> is coupled to receive power from the turbine <b>1006</b>. The controller <b>824</b> is coupled to switchably supply power to the cooler module <b>822</b> and the heaters <b>806</b>. The controller <b>824</b> is also coupled to switchably supply power to the electronics <b>820</b> and the energy storage device <b>804</b>. In some embodiments, power may be supplied to the electronics <b>820</b> and the energy storage device <b>804</b> simultaneously or to either.

0071The controller <b>824</b> may be configured to receive power from multiple sources. For example, the controller <b>824</b> may receive power from a generator and an energy storage device. Power from the generator may be allocated to and by the controller <b>824</b> in varying proportion to any or all of the energy storage device <b>804</b>, cooler module <b>822</b>, the electronics <b>820</b>, the heaters <b>806</b>, the electronics <b>820</b> (including sensors) and the controller <b>824</b>. In some embodiments, power from the energy storage device <b>804</b> may be allocated to and by the controller <b>824</b> in varying proportion to the electronics <b>820</b> (including sensors). It is possible that power from the energy storage device <b>804</b> may be allocated to the cooler module <b>822</b> or heaters <b>806</b> for a short period of time.

0072With regard to heat flow, heat may be exchanged between the heat sink <b>836</b> and the cooler module <b>822</b>. Heat may also be exchanged between the heat sink <b>835</b> and the heaters <b>8806</b>. Heat may also flow from the electronics <b>820</b> to the cooler module <b>822</b> and to the energy storage device <b>804</b>. Heat may also flow from the cooler module <b>822</b> to the environment <b>418</b> and to the heaters <b>806</b>. Heat may also flow from the heaters <b>806</b> to the energy storage device <b>804</b>.

0073The heat flow and power flows are not limited to those shown in <figref idref="DRAWINGS">FIG. 10</figref>. For example, with regard to heat flow, the direction is dependent on the relative temperatures. In some embodiments, heat flows between the electronics <b>820</b> and the heat sink <b>836</b>, between the heat sink <b>836</b> and the cooler module <b>822</b>, and between the cooler module <b>822</b> and the environment <b>418</b>. Heat may also flow between the heaters <b>806</b> and the energy storage device <b>804</b>.

0074The operations of the configuration illustrated in <figref idref="DRAWINGS">FIG. 8</figref> are now described. In particular, <figref idref="DRAWINGS">FIG. 11</figref> illustrates a flow diagram for controlling power flow between heating and cooling, according to some embodiments of the invention. The flow diagram commences at block <b>1102</b>.

0075At block <b>1102</b>, a downhole temperature (or alternatively a rate of change of the downhole temperature) is determined. With reference to <figref idref="DRAWINGS">FIG. 8</figref>, the controller <b>824</b> may make this determination. The controller <b>824</b> may make this determination based on data from one of more of the sensors downhole. For example, the controller <b>824</b> may determine the temperatures of the environment external or internal to the tool. The controller <b>824</b> may determine the temperatures of the energy storage device <b>804</b> and/or the electronics <b>820</b>. The controller <b>824</b> may also determine a temperature of one or more phase change materials within one of more of the heat sinks (e.g., the heat sink <b>835</b> or the heat sink <b>836</b>). The flow continues at block <b>1104</b>.

0076At block <b>1104</b>, power from a power source is allocated between a heater and a cooler that are part of a tool used for a downhole operation based on the downhole temperature. With reference to <figref idref="DRAWINGS">FIG. 8</figref>, the controller <b>824</b> may make this allocation. The controller <b>824</b> may allocate different percentages, all and none, etc. based on the downhole temperature. For example, if the downhole temperature is below a minimum value, the controller <b>824</b> may allocate all power to the heaters <b>806</b>. If the downhole temperature is above the minimum value but below a threshold value, the controller <b>824</b> may allocate a higher percentage of the power to the heaters <b>806</b>. If the downhole temperature is above the threshold value, the controller <b>824</b> may allocate all of the power to the cooler module <b>822</b>. In some embodiments, the controller <b>824</b> may allocate a preponderance of the power to the heaters <b>806</b>, if the downhole temperature is defined as low. The controller <b>824</b> may allocate a preponderance of the power to the cooler module <b>822</b>, if the downhole temperature is defined high. For example, a low temperature may be defined as a temperature less than 100° C.; a high temperature may be defined as a temperature of 100° C. or greater. Therefore, the controller <b>824</b> may allocate power between the heater and cooler using a number of different techniques. While described such that allocation is between the heaters and the cooler module, embodiments are not so limited. For example, the controller <b>824</b> may allocate power to other components of the tool. In particular, the controller <b>824</b> may allocate power between the heaters <b>806</b>, the cooler module <b>822</b>, the electronics <b>820</b>, the heat sinks <b>836</b>, the heat sink <b>835</b>, etc.

Downhole Rechargeable Energy Storage Device

0077In some embodiments, rechargeable energy storage devices are used to power electrical components downhole. For example, with reference to <figref idref="DRAWINGS">FIGS. 2 and 8</figref>, the energy storage device <b>203</b>/<b>804</b> may be rechargeable. The rechargeable energy storage devices may be charged by a downhole power source. For example, a turbine generator may be used to recharge the rechargeable energy storage devices. In some embodiments, the rechargeable energy storage devices may be charged at the surface. In other words, the rechargeable energy storage device is being charged prior to be placed in the well. In some embodiments, the rechargeable energy storage devices may be different types of batteries (such as molten salt batteries). The rechargeable energy storage devices may be operable at high temperatures. High temperatures at which the rechargeable energy storage devices may be operable include temperature above 60° C., above 120° C., above 175° C., above 220° C., above 600° C., in a range of 175-250° C., in a range of 220-600° C., etc. Below these temperatures, the rechargeable energy storage devices may provide electrical power but are defined as “not operable” due to an increase in internal resistance, a reduction in capacity, a reduction in cycle life, or some other temperature-dependent behavior. In some embodiments, the rechargeable energy storage devices may be operable at low temperatures. The low temperature at which the rechargeable energy storage devices are operable includes temperature below 100° C., below 150° C., below 175° C., below 200° C., below 220° C., below 125° C., below 100° C., below 80° C., in a range of 0-80° C., in a range of −20-100° C., etc. At higher temperatures, these rechargeable energy storage devices may provide electrical power but are defined as “not operable” due to an increase in self discharge, a reduction in cycle life, a reduction in current output, a decrease in safety, or some other temperature-dependent behavior.

0078The energy storage device and the rechargeable energy storage device may store energy in electro-chemical reactions, such as batteries, capacitors, and fuel cells. The energy storage device and rechargeable energy storage device may store energy in mechanical potential energy, such as springs and hydraulic assemblies, or in mechanical kinetic energy, such as flywheels and oscillating assemblies.

0079The electrical components downhole may be powered by a combination of a power source (such as a turbine generator powered by the flow of mud downhole), a vibration-based power generator powered by vibrations of the tool string, a vibration-based power generator powered by fluid-induced vibrations, a nuclear power source powered by atomic decay, a hydraulic accumulator-based power source, a gas accumulator-based power source, a flywheel-based power source, a hydrostatic dump chamber-based power source, and one or more rechargeable energy storage devices. An example of such a configuration is illustrated in <figref idref="DRAWINGS">FIG. 2</figref>. For example, the electrical components may be powered directly by the power generator while there is a sufficient fluid flow. Power not consumed by the electrical components may be used to charge the one or more rechargeable energy storage devices. During no flow condition, all or some of the electrical components may be powered by the one or more rechargeable energy storage devices. For example, when drill stands are being changed (no fluid flow), the cooling system and/or heaters may be switched off and power for select sensors and/or electronics may be supplied by the rechargeable energy storage devices.

0080Some embodiments use a controller (similar to the one shown in <figref idref="DRAWINGS">FIG. 8</figref>) to control power distribution from among a power generator, a rechargeable energy storage device and an energy storage device. Accordingly, the controller serves as a power hub to direct power from the power generator, the rechargeable energy storage device, and the energy storage device to the different electrical loads downhole. <figref idref="DRAWINGS">FIGS. 12 and 13</figref> illustrate power flow and heat flow, respectively, for parts of a tool that includes a rechargeable energy storage device, according to some embodiments of the invention. In particular, <figref idref="DRAWINGS">FIG. 12</figref> illustrates power flow in a tool for downhole operations that includes a rechargeable energy storage device, according to some embodiments of the invention.

0081As shown, a power generator <b>1206</b> and a cooler <b>1204</b> receive power from a flow <b>1208</b>. A controller is coupled to receive power from the power generator <b>1206</b>, a rechargeable energy storage device <b>1210</b> and an energy storage device <b>1214</b>. The controller <b>1202</b> distributes power to the cooler <b>1204</b> and the electronics <b>1212</b>. Accordingly, the cooler <b>1204</b> may receive power directly from the flow <b>1208</b> or from the controller <b>1202</b>. The energy storage device <b>1214</b> may also be coupled to supply power to the power generator <b>1206</b>. The controller <b>1202</b> may also distribute power from the power generator <b>1206</b> and the energy storage device <b>1214</b> to the rechargeable energy storage device <b>1210</b>.

0082<figref idref="DRAWINGS">FIG. 13</figref> illustrates heat flow in a tool for downhole operations that includes a rechargeable energy storage device, according to some embodiments of the invention. Heat may flow from a power generator <b>1306</b> and a cooler <b>1304</b> to a mud flow <b>1308</b>. Heat is exchanged between the cooler <b>1304</b> and a rechargeable storage device <b>1310</b>. Heat may also be exchanged between the cooler <b>1304</b> and an energy storage device <b>1314</b>. Accordingly, the heat from the cooler <b>1304</b> may increase the efficiency of the rechargeable storage device <b>1310</b> and the energy storage device <b>1314</b> (especially if such devices are operable at high-temperatures). Alternatively, the cooler <b>1304</b> may provide additional cooling to the rechargeable storage device <b>1310</b> and the energy storage device <b>1314</b> when the ambient temperature exceeds a maximum operating temperature for such devices. Heat may be exchanged between the cooler <b>1304</b> and electronics <b>1312</b>. Accordingly, the cooler <b>1304</b> provides cooling to the electronics <b>1312</b> by accepting heat there from. The cooler <b>1304</b> may also provide heat to the electronics <b>1312</b> if a constant temperature reference is needed. Heat may be exchanged between the rechargeable energy storage device <b>1310</b> and the energy storage device <b>1314</b>. Heat flows from electronics <b>1312</b> to the rechargeable energy storage device <b>1310</b> and the energy storage device <b>1314</b>.

0083DC power sources (such as the rechargeable energy storage devices) may provide a cleaner source of power to electrical components in comparison to AC power sources. Therefore, in some embodiments, the turbine generator (or other AC power source downhole) may be used to recharge the rechargeable energy storage devices, which then power the electrical components. In other words, in such a configuration, the power generator is not used to directly supply power to the electrical components.

0084<figref idref="DRAWINGS">FIGS. 14A and 14B</figref> illustrates different types of such configurations. <figref idref="DRAWINGS">FIG. 14A</figref> illustrates a more detailed diagram of a tool for downhole operations that includes rechargeable energy storage devices to supply power downhole, according to some embodiments of the invention. An AC power source <b>1402</b> may receive mechanical power from the fluid flow or drill string motion and may convert the mechanical power into electrical power. The AC power source <b>1402</b> may be any type of power generator (such as a turbine generator, as described above). The electrical power from the AC power source <b>1402</b> may be received by a transformer <b>1404</b>. <b>14</b> The transformer <b>1404</b> steps up or steps down the alternating current from the AC power source <b>1402</b>. The transformed current from the transformer <b>1404</b> may be coupled to be input into a rectifier <b>1406</b>. The rectifier <b>1406</b> converts the current into a DC current, which may then be used to recharge the rechargeable energy storage device <b>1408</b> and the rechargeable energy storage device <b>1410</b>. The rechargeable energy storage device <b>1408</b> and the rechargeable energy storage device <b>1410</b> may supply DC power to electronics <b>1412</b>. A controller <b>1407</b> may be coupled to the rectifier <b>1406</b>, the rechargeable energy storage device <b>1408</b> and the rechargeable energy storage device <b>1410</b>. The controller <b>807</b> controls which of the rechargeable energy storage devices is being recharged and which of the rechargeable energy storage devices is supplying power to the electronics <b>1412</b>. Accordingly, DC current power source may be used to supply power to the electronics <b>1412</b> based on an AC current power source. In some embodiments, as one rechargeable energy storage device is being recharged, the other may be being used to supply power to the electronics downhole. The controller <b>1407</b> may control the switching based on amount of energy storage in each of the devices. For example, if the rechargeable energy storage device <b>1408</b> is supplying power and is almost deplete of stored energy, the controller <b>1407</b> may switch such that the rechargeable energy storage device <b>1410</b> is supplying power while the rechargeable energy storage device is being recharged.

0085<figref idref="DRAWINGS">FIG. 14B</figref> illustrates a more detailed diagram of a tool for downhole operations that includes rechargeable energy storage devices to supply power downhole, according to other embodiments of the invention. <figref idref="DRAWINGS">FIG. 14B</figref> has a similar configuration as <figref idref="DRAWINGS">FIG. 14A</figref>. However, the rectifier <b>1406</b> first receives the power from the AC power source <b>1402</b>. A converter <b>1405</b> is coupled to receive the DC power from the rectifier <b>1406</b>. The converter <b>1405</b> may perform a DC-to-DC step-up conversion to raise the DC voltage. <b>14</b> While <figref idref="DRAWINGS">FIGS. 14A-14B</figref> are described in reference to an AC power source, embodiments are not so limited. The tool shown in <figref idref="DRAWINGS">FIGS. 14A-14B</figref> may include any other type of power.

0086Embodiments illustrated herein may be combined in various combinations. For example, the configuration of <figref idref="DRAWINGS">FIG. 8</figref> (having the controller <b>824</b> for switching between heating and cooling) may be combined with the configurations of <figref idref="DRAWINGS">FIGS. 14A-14B</figref> (having an AC power source in combination with multiple rechargeable energy storage devices).

System Operating Environments

0087System operating environments for the tool <b>100</b>, according to some embodiments, are now described. <figref idref="DRAWINGS">FIG. 15A</figref> illustrates a drilling well during wireline logging operations that includes the heating and/or cooling downhole, according to some embodiments of the invention. A drilling platform <b>1586</b> is equipped with a derrick <b>1588</b> that supports a hoist <b>1590</b>. Drilling of oil and gas wells is commonly carried out by a string of drill pipes connected together so as to form a drilling string that is lowered through a rotary table <b>1510</b> into a wellbore or borehole <b>1512</b>. Here it is assumed that the drilling string has been temporarily removed from the borehole <b>1512</b> to allow a wireline logging tool body <b>1570</b>, such as a probe or sonde, to be lowered by wireline or logging cable <b>1574</b> into the borehole <b>1512</b>. Typically, the tool body <b>1570</b> is lowered to the bottom of the region of interest and subsequently pulled upward at a substantially constant speed. During the upward trip, instruments included in the tool body <b>1570</b> may be used to perform measurements on the subsurface formations <b>1514</b> adjacent the borehole <b>1512</b> as they pass by. The measurement data can be communicated to a logging facility <b>1592</b> for storage, processing, and analysis. The logging facility <b>1592</b> may be provided with electronic equipment for various types of signal processing. Similar log data may be gathered and analyzed during drilling operations (e.g., during Logging While Drilling, or LWD operations).

0088<figref idref="DRAWINGS">FIG. 15B</figref> illustrates a drilling well during MWD operations that includes the heating and/or cooling downhole, according to some embodiments of the invention. It can be seen how a system <b>1564</b> may also form a portion of a drilling rig <b>1502</b> located at a surface <b>1504</b> of a well <b>1506</b>. The drilling rig <b>1502</b> may provide support for a drill string <b>1508</b>. The drill string <b>1508</b> may operate to penetrate a rotary table <b>1510</b> for drilling a borehole <b>1512</b> through subsurface formations <b>1514</b>. The drill string <b>1508</b> may include a Kelly <b>1516</b>, drill pipe <b>1518</b>, and a bottom hole assembly <b>1520</b>, perhaps located at the lower portion of the drill pipe <b>1518</b>.

0089The bottom hole assembly <b>1520</b> may include drill collars <b>1522</b>, a downhole tool <b>1524</b>, and a drill bit <b>1526</b>. The drill bit <b>1526</b> may operate to create a borehole <b>1512</b> by penetrating the surface <b>1504</b> and subsurface formations <b>1514</b>. The downhole tool <b>1524</b> may comprise any of a number of different types of tools including MWD (measurement while drilling) tools, LWD (logging while drilling) tools, and others.

0090During drilling operations, the drill string <b>1508</b> (perhaps including the Kelly <b>1516</b>, the drill pipe <b>1518</b>, and the bottom hole assembly <b>1520</b>) may be rotated by the rotary table <b>1510</b>. In addition to, or alternatively, the bottom hole assembly <b>1520</b> may also be rotated by a motor (e.g., a mud motor) that is located downhole. The drill collars <b>1522</b> may be used to add weight to the drill bit <b>1526</b>. The drill collars <b>1522</b> also may stiffen the bottom hole assembly <b>1520</b> to allow the bottom hole assembly <b>1520</b> to transfer the added weight to the drill bit <b>1526</b>, and in turn, assist the drill bit <b>1526</b> in penetrating the surface <b>1504</b> and subsurface formations <b>1514</b>.

0091During drilling operations, a mud pump <b>1532</b> may pump drilling fluid (sometimes known by those of skill in the art as “drilling mud”) from a mud pit <b>1534</b> through a hose <b>1536</b> into the drill pipe <b>1518</b> and down to the drill bit <b>1526</b>. The drilling fluid can flow out from the drill bit <b>1526</b> and be returned to the surface <b>1504</b> through an annular area <b>1540</b> between the drill pipe <b>1518</b> and the sides of the borehole <b>1512</b>. The drilling fluid may then be returned to the mud pit <b>1534</b>, where such fluid is filtered. In some embodiments, the drilling fluid can be used to cool the drill bit <b>1526</b>, as well as to provide lubrication for the drill bit <b>1526</b> during drilling operations. Additionally, the drilling fluid may be used to remove subsurface formation <b>1514</b> cuttings created by operating the drill bit <b>1526</b>.

General

0092In the description, numerous specific details such as logic implementations, opcodes, means to specify operands, resource partitioning/sharing/duplication implementations, types and interrelationships of system components, and logic partitioning/integration choices are set forth in order to provide a more thorough understanding of the present invention. It will be appreciated, however, by one skilled in the art that embodiments of the invention may be practiced without such specific details. In other instances, control structures, gate level circuits and full software instruction sequences have not been shown in detail in order not to obscure the embodiments of the invention. Those of ordinary skill in the art, with the included descriptions will be able to implement appropriate functionality without undue experimentation.

0093References in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

0094A number of figures show block diagrams of systems and apparatus for heating and cooling downhole, in accordance with some embodiments of the invention. A figure shows a flow diagram illustrating operations for heating and cooling downhole, in accordance with some embodiments of the invention. The operations of the flow diagram are described with references to the systems/apparatus shown in the block diagrams. However, it should be understood that the operations of the flow diagram could be performed by embodiments of systems and apparatus other than those discussed with reference to the block diagrams, and embodiments discussed with reference to the systems/apparatus could perform operations different than those discussed with reference to the flow diagram.

0095Some or all of the operations described herein may be performed by hardware, firmware, software or a combination thereof. For example, the operations of the different controllers as described herein may be performed by hardware, firmware, software or a combination thereof. Upon reading and comprehending the content of this disclosure, one of ordinary skill in the art will understand the manner in which a software program can be launched from a machine-readable medium in a computer-based system to execute the functions defined in the software program. One of ordinary skill in the art will further understand the various programming languages that may be employed to create one or more software programs designed to implement and perform the methods disclosed herein. The programs may be structured in an object-orientated format using an object-oriented language such as Java or C++. Alternatively, the programs can be structured in a procedure-orientated format using a procedural language, such as assembly or C. The software components may communicate using any of a number of mechanisms well-known to those skilled in the art, such as application program interfaces or inter-process communication techniques, including remote procedure calls. The teachings of various embodiments are not limited to any particular programming language or environment.

0096In view of the wide variety of permutations to the embodiments described herein, this detailed description is intended to be illustrative only, and should not be taken as limiting the scope of the invention. What is claimed as the invention, therefore, is all such modifications as may come within the scope and spirit of the following claims and equivalents thereto. Therefore, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.